Equivalent nosing force for a steel railway bridge based on in situ measurements

2021 ◽  
Author(s):  
Lazar Georgiev ◽  
Lyubomir Zdravkov ◽  
Vatyu Tanev ◽  
Milcho Lepoev
Keyword(s):  
In Situ Measurements ◽  
Railway Bridge ◽  
Open Type ◽  
Long Span ◽  
Out Of Plane ◽  
Design Loads ◽  
The Republic ◽  
Design Speed ◽  
Steel Railway Bridge

<p>The weight and design speed of the railway vehicles increases in time. As a result, the values of design loads grow up. In old Bulgarian standard [1] the equivalent nosing force is prescribed as 60kN. In the present EN1991-2 [2] this value is 100kN. Meanwhile, a significant part of the very old bridges is not designed for nosing forces. In cases of long span between cross girders of the “open type” deck and lack of nosing braces, the load bearing capacity of longitudinal girders, concerning out of plane bending moments due to nosing forces, is insufficient. To investigate the value of equivalent nosing force are provided “in situ” measurements on the longitudinal girders of “open type” deck of a steel riveted railway bridge in exploitation in the Republic of Bulgaria. The strains and horizontal linear deformations are measured in the midspan of the longitudinal beams for real trains. The equivalent nosing force is calculated using developed procedures.</p>

In-situ testing and model updating of a long-span cable-stayed railway bridge with hybrid girders subjected to a running train

2022 ◽  
Vol 253 ◽  
pp. 113823
Author(s):  
Hongye Gou ◽  
Tianqi Zhao ◽  
Shiqiang Qin ◽  
Xiaogang Zheng ◽  
Alessio Pipinato ◽  
...  
Keyword(s):  
Model Updating ◽  
Railway Bridge ◽  
In Situ Testing ◽  
Long Span

In-Situ Field Measurements and Numerical Model Identification of a Multi-Span Steel Railway Bridge

2014 ◽  
Vol 43 (6) ◽  
pp. 20140049 ◽  
Author(s):  
Ozden Caglayan ◽  
Kadir Ozakgul ◽  
Ovunc Tezer ◽  
Filiz Piroglu
Keyword(s):  
Numerical Model ◽  
Model Identification ◽  
Field Measurements ◽  
Railway Bridge ◽  
Steel Railway Bridge

scholarly journals Icing Cloud Microstructure from in Situ Measurements

1983 ◽  
Vol 4 ◽  
pp. 66-72 ◽  
Author(s):  
J. F. Gayet ◽  
M. Bain
Keyword(s):  
Ivory Coast ◽  
In Situ Measurements ◽  
Physical Parameters ◽  
Research Aircraft ◽  
Radar Signatures ◽  
The Republic

In several experiments carried out in France, the Republic of the Ivory Coast, and Spain, icing clouds were penetrated at different heights by instrumented research aircraft. This paper describes the range and the frequencies of occurrence of the relevant icing parameters computed on the cloud scale and for different cloud types. Comparisons between micro-physical parameters and meteorolagical radar signatures show the limitations of these radars when used as a means of locating icing clouds.

scholarly journals Evaluation of Performance Indicator of Railway Bridges Using Updated Finite Element Model

2019 ◽  
Vol 69 (2) ◽  
pp. 89-96
Author(s):  
Sokol Milan ◽  
Márföldi Monika ◽  
Venglár Michal ◽  
Lamperová Katarína
Keyword(s):  
Health Monitoring ◽  
Performance Indicator ◽  
Element Model ◽  
Fe Model ◽  
Railway Bridge ◽  
Railway Bridges ◽  
Evaluation Of Performance ◽  
Bridge Structures ◽  
Steel Railway Bridge

AbstractStructural health monitoring (SHM) can provide information needed to make important decisions regarding the maintenance of bridge structures. However, the data collected from monitoring needs to be first translated into actionable, quantitative or qualitative based characteristics, that indicate the condition of a bridge. This paper presents a process of evaluation of such performance indicator in case of a steel railway bridge using the updated FE model and in-situ measurements of strains on selected stringers and floorbeams.

scholarly journals Icing Cloud Microstructure from in Situ Measurements

1983 ◽  
Vol 4 ◽  
pp. 66-72
Author(s):  
J. F. Gayet ◽  
M. Bain
Keyword(s):  
Ivory Coast ◽  
In Situ Measurements ◽  
Physical Parameters ◽  
Research Aircraft ◽  
Radar Signatures ◽  
The Republic

In several experiments carried out in France, the Republic of the Ivory Coast, and Spain, icing clouds were penetrated at different heights by instrumented research aircraft. This paper describes the range and the frequencies of occurrence of the relevant icing parameters computed on the cloud scale and for different cloud types. Comparisons between micro-physical parameters and meteorolagical radar signatures show the limitations of these radars when used as a means of locating icing clouds.

scholarly journals Fatigue Analysis of a Railway Steel Bridge

2018 ◽  
Vol 7 (3.12) ◽  
pp. 1098 ◽  
Author(s):  
Kandagatla Viswanatj ◽  
M Ravi Kumar
Keyword(s):  
Fatigue Life ◽  
Fatigue Loading ◽  
Critical Section ◽  
Point Of View ◽  
Elastic Behaviour ◽  
Steel Bridge ◽  
Railway Bridge ◽  
Design Loads ◽  
Steel Railway Bridge ◽  
Coefficient Method

One of the significant means of transportation in India are railways and has many steel bridges which are very old having historical importance and their design period is terminating. To appraisal, the levels of damage for workable repairs, stands a tedious job for government authorities. The prediction of fatigue life of bridges are important because at present these are subjected to elephantine loads than the design loads and the environmental conditions boost these aspects to turn up fatigue life. This paper studies the analytical analysis of a steel railway bridge subjected to EURO and INDIAN fatigue loading to evaluate the fatigue life of a bridge and stresses are calculated from S-N curves by nominal stress method. The fatigue verification has been done by λ-coefficient method. Fatigue life of critical section was found out by sub-modelling the welded joint where the stress are maximum. The crack initiation starts at powerless members and propagates it along the section leads to fracture the entire structure under elastic behaviour. Hence, if the results of the critical section are satisfactory, it can be concluded that entire bridge is safe in fatigue point of view. INDIAN HM loadings generate more damage than EURO LM-71 loading.  

The Carbon:²³⁴Thorium ratios of sinking particles in the California Current Ecosystem 2: Examination of a thorium sorption, desorption, and particle transport model

2019 ◽  
Author(s):  
Michael Stukel ◽  
Thomas Kelly
Keyword(s):  
Organic Carbon ◽  
Water Column ◽  
Particulate Organic Carbon ◽  
Transport Model ◽  
California Current ◽  
In Situ Measurements ◽  
Power Law Distribution ◽  
Sinking Particles ◽  
Organic Carbon Concentration

Thorium-234 (234Th) is a powerful tracer of particle dynamics and the biological pump in the surface ocean; however, variability in carbon:thorium ratios of sinking particles adds substantial uncertainty to estimates of organic carbon export. We coupled a mechanistic thorium sorption and desorption model to a one-dimensional particle sinking model that uses realistic particle settling velocity spectra. The model generates estimates of 238U-234Th disequilibrium, particulate organic carbon concentration, and the C:234Th ratio of sinking particles, which are then compared to in situ measurements from quasi-Lagrangian studies conducted on six cruises in the California Current Ecosystem. Broad patterns observed in in situ measurements, including decreasing C:234Th ratios with depth and a strong correlation between sinking C:234Th and the ratio of vertically-integrated particulate organic carbon (POC) to vertically-integrated total water column 234Th, were accurately recovered by models assuming either a power law distribution of sinking speeds or a double log normal distribution of sinking speeds. Simulations suggested that the observed decrease in C:234Th with depth may be driven by preferential remineralization of carbon by particle-attached microbes. However, an alternate model structure featuring complete consumption and/or disaggregation of particles by mesozooplankton (e.g. no preferential remineralization of carbon) was also able to simulate decreasing C:234Th with depth (although the decrease was weaker), driven by 234Th adsorption onto slowly sinking particles. Model results also suggest that during bloom decays C:234Th ratios of sinking particles should be higher than expected (based on contemporaneous water column POC), because high settling velocities minimize carbon remineralization during sinking.

Evaluation of reanalysis and satellite-based sea surface winds using in situ measurements from Chinese Antarctic Expeditions

2013 ◽  
Vol 24 (3) ◽  
pp. 147
Author(s):  
Ming LI ◽  
Qinghua YANG ◽  
Jiechen ZHAO ◽  
Lin ZHANG ◽  
Chunhua LI ◽  
...  
Keyword(s):  
In Situ Measurements ◽  
Sea Surface ◽  
Surface Winds ◽  
Sea Surface Winds
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